<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
</head>

<body>
    <div style="background-color: red; width: 300px; height: 200px; display: none;">
        HelloWorld1
    </div>
    <div style="
        background-color: green;
        width: 300px;
        height: 200px;
        display: block;
      ">
        HelloWorld2
    </div>
    <div style="
        background-color: gray;
        width: 300px;
        height: 200px;
        display: block;
      ">
        HelloWorld2
    </div>
    <div style="
        background-color: blue;
        width: 300px;
        height: 200px;
        float: left;
        display: inline;
      ">
        HelloWorld3
    </div>
    <div style="
        background-color: orange;
        width: 300px;
        height: 200px;
        float: left;
        display: inline;
      ">
        HelloWorld4
    </div>
</body>

</html>